Calculating machine



' Oct. 10', 1950 G. v. NOLDE CALCULATING MACHINE l0 Sheets-Sheet 1 Original Filed March l,- 1948 INVENTOR George V A/a/c/e Oct, 10, 1950 s. v. NOLDE 2,525,423

CALCULATING MACHINE Original Filed M rch 1, 194a 1o Sheets-Sheet 3 e 0 R v MM M m m hfnml W m a m 0. e 4 Q4! 4 u A. 4 r H. 6 M m NVW MW e lWr'W! EM} a a e Oct. 10, 1950 e; v. NOLDE CALCULATING MACHINE 10 Sheets-Sheet 4 Original Filed March 1, 1948 2&5 547 v 550 5/).6.

' mvamona Geo/ye L A/a/oe Oct. 10, 1950 G. v. NOLDE CALCULATING cam:

10 Sheets-Sheet 6 Original Filed March 1, 1948 m Q Rm 5% 3 NIQM 5% x 3 Q3 QQQ MNQ NE 5 m Q an s3 mm 6 M 0 w W I m 0 e 6 Oct. 10, 1950 v, NQLDE 2,525,423

\ CALCULATING MACHINE Original Filed March 1, 1948 l0 Shets-Sheet 7 INVENTOR Geo/"ye L .A/o/oe Oct. 10, 1950 a. v. NOLDE 2,525,423

CALCULATING MACHINE Original Filed March 1', 1948 10 Sheets-Sheet 9 o\ co O' *0 '3 N e o rye L A/o/oe BY 440.42. M

Oct. 10, 1950 G. v. NOLDE CALCULATING MACHINE 10 Sheets-Sheet 10 Original Filed March 1, 1948 m m-md. ll r a St is QMR 3! so u o: aw w$ j R3 is R QR 8 v 4 NSQ Jon xwm V INVENTOR; Gee/ye L/ A/a/de Patented Qct. 10, 1950 CALCULATING MACHINE George V. Nolde, Berkeley, Calif., assignor to Marchant Calculating Machine Company, a corporation of California Original application March 1, 1948, 'Serial N6. 12,232. Divided and this application November 30, 1948, Serial No. 62,760

7 Claims. (01. 235-49) The present invention relates to calculating machines and particularly concerns improvements in division control mechanisms.

This case is a division of the application,

, Serial Number 12,232, filed March 1', 1948. The

machine disclosed in said application is adapted for simultaneous operation of the actuating and shifting mechanisms. Each numeral wheel of the accumulator or dividend register is permanently associated with a respective actuator. Each ordinal actuator comprises a series of ten selectively engageable differential clutches representing the values 1 to 9 and 0, respectively. The clutches l to 9 are provided for driving the numeral wheel by differential amounts while the clutch prevents operation of the numeral wheel by the actuating mechanism. The clutches are selectively engaged under the control of a plural order selection storing carriage which comprises, in each order thereof, ten selectively settable clutch engaging elements. These elements are set to clutch engaging posi tion by a single order selection set-nip carriage which is controled by the numeral keys of a ten-key keyboard. The selection storing carriage is effective prior to each actuating operation to cause engagement of a selected one of the differential clutches.

The selection storing carriage comprises a fewer number of orders than the accumulator, and is shiftable relative to the accumulator numeral wheels and their respective clutches. Once a differential clutch is engaged by'the selection storing carriage, it remains engaged throughout an ordinal actuating operation, during which the selection storing carriage'is shifted to another order of the actuating mechanism in preparation for thenext actuating operation. The present invention utilizes this mechan sm in the performance of division calculations. The above mentioned simultaneously operable actuating and shifting mechanism is fully described in said application to which reference'may be had for a full understanding of the operation thereof.

A dividend sensing mechanism is provided which is effective in each ordinal operation of the division mechan sm to sense the value of the dividend, or remainder of the dividend as the case may be, while a divisor sensing mechanism sensesthe value of the divisor. The respective values so sensed are compared in a 1pre-estimating mechanism of the type shown and disclosed in the Avery application, Serial Number 81,501, filed March 15, 1949, to obtain an estimated quotient digit, the representation of which controls the number of cycles of subtractive actuation of the current ordinal operation.

The adjustment of the pre-estimating mechanism preferably is such that the machine will pre-estimate the correct quotient digit. In some cases, however, it may pre-estimate one more than the correct quotient digit, in which case the divisor is subtracted'once too often from the current dividend and an overdraft results. At the end of each subtractive actuation, the value of the. remainder is sensed to determine whether or not an overdraft has occurred. If an overdraft condition is sensed, a corrective plus stroke is initiated, during which a shifting operation is initiated and completed. If an overdraft condition is not sensed, then a corrective plus stroke is not required and instead an ordinal shift'is automatically initiated, at the conclusion of which the next ordinal division operation is automatically started.

The dividend register is of the'crawl carry type by means of which partial tens carry increments are entered simultaneous with digitation; Then upon completion ofdigitation these partialtens carry increments are backed out to align the numeral wheels. For this purpose a correction at entry compensating mechanism is provided. Normally the aligning operation does not cause a vdelay in division operations. In case of an overdraft, however, a carry Wave results, during which the numeral wheels are changed from zeros to nines in the manner described in U. S. patent, Number 2,222,164 issued to Harold T. Avery, November 19, 1940, and which carry wave delays the alignment of the numeral wheels. Since the dividendvalue determining means is adaptedfor sensing the value of the dividend when thenumeral wheels are in aligned position, a mechanismcomprising a part of the present invention is provided for delaying each dividend valuesensing operation for a period of time suiticient to allow any possible carry wave to be completed. In many cases, however, there will be no overdraft to delay the alignment of the nilmeral wheels: therefore, a second mechanism is provided to supersede the delay mechanism and initiate a sensing operation when the values standing. in certain orders of the dividend register indicate that a carry wave through those laying mechanism and initiating a sensing operation when certain orders of the dividend register stand at values that indicate a carry wave is not possible, and (3) initiating a simultaneous plus stroke and shifting operation under the control of the dividend sensing mechanism when the latter senses an overdraft.

A principal object of the present invention is to shift a dividend value determining device from one order of the dividend register to the next lower order thereof during a value enterillg operation of the actuators.-

Another object is to shift the actuator control mechanism from one group of orders of the actuating means to the next lower group thereof during a corrective plus stroke of the actuating means.

It is still another object to delay the above mentioned sensing and shifting o erations and other operations incident to division calculations when a carry wave is possible and to eliminate such delays when a carry wave is not possible.

A further object of the invention is to provide a calculating machine of the above character embodying an improved form of pre-estimation division mechanism.

Other objects and advantages of the invention will be apparent from the following description of a preferred embodiment of the invention, as illustrated in the accompanying drawings, in which:

Fig. 1 is a longitudinal section of the machine as viewed from the right showing the general arrangement c-f the machine with the exception I of the keyboard which has been omitted.

Fig. 2 is a right s de detail View of the variable resistance contacts associated with a numeral wheel of the divi or factor indicator.

Fig. 3 is an enlarged sectional elevation taken on line 33 of Fig 1.

Fig. 4 is a fragmentary section as seen from the left side of the machine and taken as indicat d by the line 4-4 in Fig. 3.

Fig. 5 is a right side view of the machine with certain parts omitted, illustrating a pair of setting clutch cams and related control mechanisms operat d th reby.

Fig. 6 is an enlarged sectional lan view of the mechanism for disablin the control of the compen atin arms of the counter register.

Fig. '7 is a. detail view of a part of the mechanism s own in Fi 6.

Fig. 8 is a right s de sectional View of the shift clutch and associated mechanisms.

Fig. 9 is a fra mentary plan view of the shift clutch and associated mechanisms.

Fig. 10 is a detailed view of a rtion of the shift drive mechanism shown in Fig. 8.

Fig. 11 is a right side view of the control switches associated with the bridge magnets of the division mechanism.

Fig. 12 is an enlar ed front view of a bridge magnet taken as indicated by the line I2I2 in Fig. 11.

Fig. 13 is an enlar ed view of a portion of the switch mechanism shown in Fig. 11.

Fig. 14 is a front view. partially in section, of the main clutch, the shift clutch, and associated mechanism.

Fig. 15 is a right side view, partially in section, showing the division control keys and their related division control mechanisms.

Fig. 16 is a fragmentary plan view of a por tion Of the division control mechanism.

Figs. 17-20 inclusive are fragmentary right side views of portions of the division control mechanism shown in Figs. 15 and 16.

Fig. 21 is an enlarged fragmentary section, as viewed from the right, showing the control mechanism for delaying return of the centralizer pawls at the ends of a digitation operation.

Fig. 22 is a left side view of the switching mechanism which is set under control of a dividend sensing carriage and which is effective to adjust the dividend resistors of the quotient estimating mechanism.

Fig. 23 is a sectional plan view of the mechanism shown in Fig. 21.

Figs. 24 and 25, taken together, form a schematic wirin diagram of the electrical controls of the calculating machine.

SELECTION MECHANISM The machine embodying the present invention includes a ten key keyboard (not shown) for entering factor digits into the machine. The numeral keys of the keyboard are operable to rock the selection shafts I50 to I59 (Fig. 1). A plurality of setting levers 220 to 229 are slideably keyed to the respective shafts Hill-I59 and are carried by a shiftable single order set-up carriage 2| I. The setting lever which is rocked by its respective key, rocks a blocking lever 3I0 to 3I5 into a position in which it later causes engagement of a respective one of an ordinal row of clutches 400. The downward y extending arm of the setting lever 220 to 229 is concurrently operable to set a respective one of a plurality of blocking interponents 250 to 259 which in turn control the movement of a selection bar 23I--23la and limit the rotation of the factor indicator numeral wheel 23I to a position corresponding to the value of the key depressed. The depression of a numeral key a so causes escapement of the set-up carriage 2| I which moves one order toward the right and into alignment with the next ordinal row of blocking levers 3H] to 3I9 and the corresponding ordinal row of interponents 250 to 259 whereupon depression of a selected numeral key will cause a similar setting of the next digit into the storing carriage MI and the next lower order numeral wheel 23I, all as described in detail in the application Serial Number 12,232 of which this is a division. Reference may be had to the above app ication for a complete disclosure of parts of the machine not specifically described herein; it being noted that parts shown in the drawings, but not described in this specification will be found to bear the same reference numerals used to identify the corresponding parts in said application. The parts identified by the same reference numerals in the drawings of this application operate exactly as shown and described in said application.

ACTUATORS The above mentioned blocking levers 3I0 to 3I9 are effective to control the engagement of a respective one of the differential clutches 400. There is a row of such clutches for each accumulator numeral wheel Mil (Fig. 3), there being approximatel twice the number of accumulator or dividend numeral whee s as there are orders in the selection storing carriage. During multi-order operations such as division, which require changing the ordinal relationship between the divisor and dividend factors or the remainder of the latter, the storing carriage 30I which contains the d sor factor is shifted one order toward the right during each ordinal operation to associate the factor set therein with the successively lower orders of the register and the numeral wheel clutches 400. The differential clutches 400 each include a driving and a driven element. The driving elements 408 are mountedfor limited sliding movement upon their respectiveshafts 350 to 359, and in each order one ofthe elements is moved into engagement with a driven element 401 by an associated fork 4l0-4I9. These forks are carried. by a clutch engaging frame 420 which is mounted for up and down movement under the control of a setting clutch. This clutch operates prior to each operation of the main clutch. Downward movement of the differential clutch engaging frame 420 brings the substantially horizontal lower surface of the fork against one of the blocking levers 3) to 319 previously moved into blocking position by a numeral key, and in so doing the fork is rocked clockwise to engage the teeth of the clutch driving element 408 with the single tooth of the clutch driven element 40'! and thus cause engagement of the selected one of the differential clutches.

Concurrent with the operation of the clutch engaging frame 420, a clutch disengaging frame generally designated at 430 (Figs. 1 and 3), is moved toward. the left as viewed in Fig. 3 by the setting clutch to disengage any previously set clutches. Frame 430 is returned toward the right before the clutch engaging frame 420 is moved upwardly to ineffective position so as not to disengage any'clutches currently being set.

The selection storing carriage l (Fig. 1) is suitably mounted in the machine for shifting relative to various orders of the ordinally arranged clutches 400. Shifting is effected by a worm shaft 308 which is rotated by operation of a shift clutch described hereinafter.

For convenience the clutches shown in the various parts of the drawings and referred to hereinafter are identified by characteristic letters such as M. C. for main clutch, S. C. for setting clutch, Sh. C. for shift clutch and C. C. for clear clutch. The cams driven by the respective clutches and the solenoids and clutch control dogs which cause engagement and disengagement of the respective clutches are also identified by'similar letters.

The gear train on the ends of shafts I-359 is such that proportional movements are transmitted to the shafts and their respective clutches 400 in ratios according to the values 1 to 9, respectively so that when one of these driving movements is transmitted to a relatednumeral wheel 46l (Fig. 1) of the register I00 there will be produced from 1 to 9 digital increments of rotation of that numeral wheel in accordance with the digital value to be entered in that order. If a zero is selected in a given order, the 0 clutch 400 is engaged and the fixed shaft 350 serves as a lock to prevent rotation of the numeral wheel during idle rotation of the other shafts 351-359. A spring detent 421 (Fig. 4) fixed to a cross member 425 of the clutch engaging frame cooperates with a pin 426 carried by the clutch engaging fork to hold the fork and a respective clutch 400 in either its engaged or disengaged position.

Each driven element 401 (Fig. 3) of the clutches 400 carries a respective gear 390-399 (Fig. l), and each ordinal series of gears 390-399 is enmeshed to form an idler gear train. Enmeshed with the idler gear train is a drive receiving gear 40! journaled on a shaft 402. The drive from gear MI is transmitted to an associated numeral wheel 46! through the crawl carry gearing as described in said 'applicationSerial Number 12,232. Upon engagement of the #1 clutch 400 for example, the main clutch drives shaft 35!, the ordinal clutch 400 associated therewith, gear 391, the gear 4! and the crawl carry gearing to advance the numeral-wheel one digital increment.

From the foregoing description of the selection mechanism, it will be apparent that the provision of the same or substantially the same number of 9 the actuating means during the operation of the latter. In this way a substantial saving in the over-all operating time of the machine in performing a calculation is made possible.

DIVIDEND REGISTER The dividend register I00 (Figs. 1 and 3) is of the crawl carry type disclosed in Patent No. 2,222,164, issued November 19, 1940. Each dividend register numeral wheel 46! has associated therewith a graduated member in the form of a snail cam 482 which is advanced with the numeral wheel and which forms a mechanical representation of the value standing in said wheel. As will be shown hereinafter, the peripheries of certain higher order snail cams are sensed to determine the approximate value standing in the dividend register.

Also associated with each numeral wheel is a pawl 46'! (Fig. l) which operates to centralize the numeral wheel after actuation thereof, and a compensation arm 483 which cooperates with the snail cam 482 to form a part of the numeral wheel aligning mechanism. The latter mechanism is of the type disclosed in Patent No. 2,089,682, issued Aug. 10, 1937, and by means of which partial carry increments are backed out of a numeral wheel through adjustment of the digital entry leg of the crawl carr gear train. During the previously mentioned setting clutch operation, the setting clutch cam 6H5 (Fig. 5) operates through the linkage shown to move both the centralizerpawls 461 and the compensation arms 483 of the dividend register to inactive positions. Pawls 461 and arms 483 are then looked in this position throughout operation of the actuating mechanism to permit free rotation of the numeral wheels and the. snail cams, respec-. tively., The centralizer pawls 155 and the compensation arms 156 for a counter register, de-

scribed hereinafter are similarly moved to, and locked in disabled positions all of which is described in the application S. N. 12,232.

REVOLUTIONS COUNTER 10! each of which is driven by a respective drive gear 193 through a planetary gear train indicated generally at 192. Each gear 103 is driven by a respective ordinal clutch similar to the ordinal clutches 400 of the actuating mechanism for the dividend register, there being only one clutch 100 for each order of the counter register in contrast to the plurality of clutches 466 for each order of the accumulating mechanism.

A shiftable interponent H6 (Fig. 1) similar in operation to the blocking levers 3lfl-3l 9 of the selection storing carriage 301 is provided to cause engagement of one of the ordinal counter clutches 100. A clutch engaging frame 101 and a clutch disengaging frame 13! are provided for the counter clutches 100 and the operation of these frames is similar to the corresponding frames 42! and 436 for the clutches 400. The arrangement is such that engagement of a clutch 166 causes a single count to be entered into an order of the counter register during each cycle of operation of the actuating mechanism. The interponent H6 is driven by a worm shaft H8 for shifting of the interponent from one order of the counter register to the next so that successive clutches 100 may be engaged. Such engagement causes successive numeral wheels 'IUI to count the number of times the multi-order divisor factor is subtracted from the dividend numeral wheels and thereby indicate the quotient digits.

MOTOR DRIVE MECHANISM The motor drive mechanism of the present machine is the same as shown in application S. N. 12,232 and includes an electric motor from which four separate drive trains are provided through a main clutch, a shift clutch, a setting clutch and a clear clutch.

MAIN CLUTCH The main clutch |5 (Fig. 5) drives through a train of gears to rotate the differential actuator shafts l-358 (Figs. 1 and 5) in amounts proportionate to the values 1 to 9. Shaft 350 is locked against driving as previously mentioned.

The main clutch also serves through a suitable drive train shown in said application S. N. 12232 to drive one of the clutches 109 and to enter a single increment of count into a selected order of the counter register it]! during each cycle of operation of the main clutch.

CYCLIC CONTROL OF ACTUATING MECHANISM The clutch control dog 5|6 (Fig. 5) for the main clutch 5l5 is rocked to clutch-engaging position by the setting clutch cam 613 and is held in clutch-engaging position by a latch (not shown) The latch and its related control devices, which are all fully described in the last mentioned application is selectively operable to hold the main clutch dog in engaged position for a pre-determined number of cycles of operation of the main clutch. Such selective operation of the clutch is under the control of a series of electromagnets 8511 to 859, diagrammatically illustrated in Fig. 24. Each magnet has a bias winding 85 la to 859a, the purpose of which is described in the last mentioned application, and also an actuating winding 85ib il5ilb, the energization of one of which causes the above mentioned selective operation of the latch. Energization of a respective actuating winding is controlled by a quotient pre-estimation mechanism including the Wheatstone bridge generally indicated at [345 (Fig. 25) and the relays I360 to I389 (Fig. 24) connected across this bridge. The Wheatstone bridge and the relays are fully described in the section on division operations.

MAIN REVERSE MECHANISM A main reverse drive unit is settable under the control of a main reverse magnet as disclosed in said application S. N. 12,232, to reverse the direction of operation of shaft 524 (Fig. 1) and toreverse the drive from the main clutch to the actuator shafts 35l-359. A similar counter reverse unit is settable under the control of a counter reverse magnet to reverse the direction of operation of shaft 146, to reverse the drive to the drive shaft 705 and the clutches for the counter register. The respective controls over these reverse units will be described more fully in the section on division operations.

SHIFT CLUTCH The shift clutch 55D (Figs. 8 and 9) operates to effect ordinal shifting movement of some of the component parts of the machine including the selection storing carriage 30! (Fig. l) and the ordinal control interponent H6 of the revolutions counter, as Well as various elements of the divison control mechanism, described hereinafter. The shift clutch is a half revolution clutch and corresponds to the clutch of the same number in the parent application.

The engagement of the shift clutch 550 (Fig. 8) is under control of a shift control solenoid 559 and a clutch control dog 556. Each cycle of operation of the half-revolution shift clutch 550 (Fig. 9) drives the cams 564, 565, 566 and 561 a full revolution. The operation of the cams 564, 565 and 566 will be described in greater detail hereinafter in conjunction with the associated mechanisms with which they cooperate.

Cam 561' (Fig. 10) forms a part of the general shift drive of the machine and, with other associated mechanisms, serves to advance certain of the shiftable parts of the machine one step for each cycle of movement of the shift clutch. The

( shift clutch cam 56? (Fig. 10) operates through a follower 568 and an actuating pawl 569 to advancea shift ratchet 5' one step for each cycle of shift clutch operation, the pawl 512 engaging successive teeth of ratchet 5l| to hold the latter in its advanced position.

Each time the ratchet 5H is advanced one step, various ordinally shiftable elements of the machine are shifted one order. These elements include the selection storing carriage 30! (Fig. 1) shiftable by means of the worm shaft 308, and the counter actuating means interponent H6 shiftable by means of the worm shaft H8. The shift drive to the worm shafts 308 (Fig. 8) and H8 is transmitted from ratchet 5H by respective gear trains described in detail in the last mentioned application. The drive from the above described pawl and ratchet mechanism is also transmitted through means hereinafter described to effect shifting of a division sensing carriage.

SETTING CLUTCH A setting clutch which is fully described in the application S. N. 12,232 operates to condition the machine for subsequent operation under control of the main clutch.

The setting clutch drives the sleeve BIZ (Fig. 5) to rotate various operating cams including cam 618 which operates through follower I88 and the linkage shown to move the numeral .tie'nt digit.

' wheel centralizer pawls 461 and 155 .and the compensation arms 483 and 156 to the disabled positions described hereinbefore. Setting clutch cam 6I3 operates through follower 63I and shaft 508 to move the main clutch dog 5I6 to clutch engaging position. As shown diagrammatically in Fig. 24, the setting clutch cam 6I9 closes a switch 630 in the circuit of the shift clutch solenoid 559 during the cycle of operation of the setting clutch. As will be disclosed hereinafter another setting clutch cam is operative during division operations to control certain elements of the division mechanism.

CLEAR CLUTCH A clear clutch is provided to'normalize all or selective portions of the machine depending DIVISION The division mechanism of the instant invention is of the general type disclosed in the copending application of. Harold T. Avery, S. N. 81,501, filed March 15, 1949, for Calculating Machines. As fully explained in the above noted Avery application, the division control is exercised in accordance with a process of pre-estimation division by means of which the divisor is comparedwith the dividend to obtain an esti- .mated quotient digit which is either the correct quotient digit or one greater than the correct quotient 'digit. At the end of an ordinal division or subtracting operation, the remainder is sensed to determine whether an overdraft has occurred due to an over-estimation of the quo- If the correct quotient digit was estimated, a relative shifting is effected between the current dividend value standing in the register E26 and the divisor, the latter being represented by the value standing in the selection storing carriage, while if the quotient figure has been over-estimated a corrective addition cycle occurs during which time the shifting of the selection storing carriageis effected.

In the performance of division operations, the above described general control operations occur in determining each quotient digit until the capacity of the machine has been reached or until the division stop key I21 is operated to terminate the division operation at the end of a desired ordinal division.

The present type of machine differs from the machine shown in the above noted Avery application in that a crawl type tens transfer registering mechanism and a modification of the proportional gear actuating mechanism is used instead of the simultaneous transfer mechanism and the dial clutch actuators disclosed in said as will be described hereinafter.

DIVIDEND ENTRY The dividend may be entered into register I08 by depression of a dividend entry (-5-) key or it may be some value previously accumulated in the register.

Depression of the dividend entry key I26 (Fig. 15) causes a value previously set up in the selection storing carriage 30I (Fig. 1) to be entered into the dividend register I00 as described fully in the aforementioned application S. N. 12,232, and after such entry the key I26 causes operation of the clear clutch to clear the counter register lel and restore both the selection storing carriage 3I3I and the selection set-up carriage 2!! to their respective initial positions. In case anaccumulated value is to be used as a dividend, then certain respective clear keys are depressed to clear the counter register IIlI and restore the carriages 3M and 2H to initial positions.

The divisor is then entered into the selection storing carriage 3E|I (Fig. l) in the usual manner through the tenskey keyboard and the value selected is shown in indicator I02.

DIVISION START OR EQUAL KEY The operation of the division start or equal key I28 (Fig. 15) serves several functions including the enabling of the division control mechanism, the disabling of a portionof a multiplication control mechanism and the conditioning of the division control mechanism for stopping the machine at the end of the division operation. 2

Referring to Fig. 15, the stem I25I of the key I28 is urged to raised position by a spring I252 and carries an ear I25Ia. overlying an arm I253 pinned to a shaft I254. Also associated with the ear I25Ia is a spring-urged latch I255 carried by a shaft I251 and serves to latch thekey I28 in depressed position as disclosed hereinafter.

The arm I253 (Fig. 15) and the shaft I254 form part of a division setting control linkage including a depending arm I255 fixed to the shaft I254 and which arm I255 is pivotally connected to a rearwardly extending division control link I258.

The latter is slotted at its rearward end to engage a support stud I262 and is urged to the right as viewed in Fig. 15 by a spring I259 connected between the link and a suitable frame bracket I26I.

To enable latching of the division start key in depressed position and to enable the division control mechanism and simultaneously disable the multiplication control mechanism, the slide I258 carries an auxiliary control slide I265 which is mounted by pin and slot connections on the slide I258 for limited movement relative thereto. Slide I266 is urged to the right as viewed in Fig. 15 by a spring I261. At its forward end the slide I266 has a laterally extending ear I266a lying in front of an arm I258 pinned to the shaft I251 for the key latch I256, so that when the slide I266 is moved to theleft, arm I268 and the latch I256 can move under the influence of the latch spring I663 to overlie the ear I 25Ia of the key I28. When key I28 is latched in depressed position, slide I258 11 slide I266 will be moved therewith. It will be noted that ear I288a is also operatively related to respective ears on levers I29I and I286d as is more fully described hereinafter.

Slide I266 controls the enabling and disabling, respectively, of the division and multiplication control mechanisms through an insulated depending arm I266b (Fig. 15) which, upon movement of the slide to the left, is adapted to open the normally closed switch 9I2 (Figs. 15 and 24) of the multiplier control circuit and close the normally opened switch I269 of the division control mechanism, the closure of switch I269 causing energization of the bias windings of a plurality of division bridge relays later described. At such time, the arm I266b also opens the normally closed switch I2'II which is in the multiplication control circuit of the shift clutch solenoid 559 and closes the switch I212 in an alternate circuit of this solenoid for control thereof during division. Thus the respective control circuits for the multiplication and division mechanisms are isolated from each other and are enabled selectively, depending upon the position of the auxiliary control slide I266.

The leftward movement of the division control slide I258 is operative to control the setting of a division control means including a division conditioning or setting lever I28I (Fig. and a division control arm I282 (Fig. 18). The lever .I28I (Fig. 20) is pinned to a control shaft I283 while the division control arm I282 (Fig. 18) is freely pivoted thereon. The lever I28I and the arm I282 have respective opposed ears I28Ia and ;I282a whichare connected by a spring I284 (Fig.

.start latch I286 (Fig. 18) and a start latch lever I29I (Fig. 20) both freely pivoted on the support shaft I281. Restart latch I286 (Fig. 18) is urged counterclockwise by spring I219 and the horizontal leftwardly extending arm I286a. is notched to engage the ear I 28Ia to maintain the division setting lever I 28I in the normal disabled position shown. A downwardly extending arm I286d secured to the hub of bell crank restart latch I286 abuts the ear I288a of the previously mentioned bell crank I288 (Fig. 15) pivoted on the control slide I 258. Latch lever I 29I (Fig. 20), previously mentioned, is freely pivoted on the shaft I28! and is biased counter-clockwise by a spring I292. An ear I29Ia on the lower arm of the latch lever I29I abuts the ear I288a, of the bell crank I288. Both of the latches I286 and I29I for the division setting lever I28I are moved to release said lever upon movement of the division control slide I258 and bell crank ear I288a to the left as viewed in Fig. 15. A cam I285 (Fig. 17) is related to an arm I28Ib on the hub of lever I28I and is driven by the main clutch to restore the lever I28I to the position shown as explained hereinafter. The upper arm I286b of the restart latch I286 (Fig. 18) is operatively related to the cam 566 driven by the shift clutch as is more fully explained hereinafter.

Associated with the division control ,arm I282 is a normally ineffective latch lever I293 (Fig. 17)

freely pivoted on the shaft I 28'! and urged counter-clockwise by a spring I 294 against an arm I295 pinned to the main clutch dog control shaft When arm I282 is released from latches I286 and I 29f to rock counter-clockwise, as described above, then a subsequent rocking of the main clutch dog shaft 508 to clutch engaging position enables latch I293 to lock the arm I282 in its counter-clockwise position. In such position arm I282 controls negative division operations through the operation of a plurality of switches I3II, I3I8, I3I9, and I320 shown in Figs. 15 and 24 and which switches are more fully described hereinafter.

With further reference to Fig. 15, it will be noted that upon movement of the division setting slide I258 to the left, i. e., to active position, that the bell crank I288, after performing its function of moving the slide I266 and the latches I286 and I29I to the above described positions, engages a stud I296 and is rocked to and held in an inactive position against the urgency of its associated spring I289 as long as slide I258 is held in its leftmost position.

The division control arm I 282, after its original release from the latches I266 and I29I, is automatically reciprocated under the control of various cams, described hereinafter, to open and close the above mentioned switches and thereby control division operations.

Means are provided for latching the auxiliary division control slide I266 in its leftmost position and this means includes the latches I30I and I306 (Figs. 15 and 16). Latch I30I is freely mounted on a shaft I308 and is urged clockwise by the spring I302 to normally lie on top of the ear I266c (Fig. 16) of the auxiliary division slide I266. Latch I30I is provided with a laterally extending ear I303 (Figs. 15 and 18) which, upon operation of the cam 566 (Fig. 18), is engaged by the depending arm I266c of the bell crank latch I286 to rock latch I30I counter-clockwise as is more fully explained hereinafter. The second latching means for the division control slide I266 is the broadfaced latch I306 (Fig. 16) which is pinned to shaft I308 and is urged clockwise to active position by the spring I301 (Fig. 20). Latch I306 normally lies on top of the ear I266c of the auxiliary division slide I266 previously referred to and also on top of an ear I29Ia of the start latch I29I. Upon depression of the division start key I28 (Fig. 15), ear I266c of link I266 and ear I29Ia of latch I29I are moved to the left, at which time the latches I30I and I306 rock clockwise to active locking positions, the latch I306 having its latching edge displaced to the left of the similar latching edge of the latch I 30I so that when the latch I 306 becomes effective with regard to the auxiliary division slide I266, the latter is held spaced from the latch I30I although the latch I30I is in position to engage the slide I266 if it is released from the latch I306. Because of the width of the face of latch I 306, it is also effective to engage and hold the latch I29I (Fig. 20) inactive when the latter is moved to its disabled position. Latch I30I is employed at the end of a division operation as later described to insure a correct quotient figure by what is known in the art as digit completion.

The movement of the start latch I29I to its disabled position with respect to lever I 28I causes enabling of a dividend sensing mechanism hereinafter described. Simultaneously with the enabling of the division sensing mechanism, certain means for comparing the dividend with the divisor are also enabled, as will now be described. The latch lever I29I' (Fig. 20) is provided with a suitable hub I29Ib carrying an auxiliary latch arm I291 (Fig. 19) normally engaging an ear I3Il9a of a lever I309. The latter lever is-freely pivoted on the shaft I283 and is urged counterclockwise by a spring I3I'0. The upper end of the lever I309 is pivotally connected to a control link I3II (Fig. 15) the opposite end of which is pivotally connected at I3I2 to an arm I3I3 of the dividend sensing carriage generally designated at I32I and which carriage is described hereinafter. Associated with the. lever. I309 (Fig. 19) is a spring-urged bell crank I3I5 having ears I3I5a and I3I5b. Ear I3I5a is operatively related 'to thedivision conditioning lever I28I (Fig. 17) and ear I5I3b is operatively related to lever 1309 (Fig. 19). Bell crank I3I5 cooperates with a cam 565 driven by the shift clutch to restore the levers 'I29I and I309 to the positions shown as will appear later.

The link I3I I (Fig. is provided with an ear I3IIa of insulating material adjacent the nor- "mally opened contacts of a switch I314 which is in the circuit of the electrical division control circuit described more particularly hereinafter. The timing of the closing of switch I3i4 by leftward movement of link I3II is such that the switch is closed during the last portion of such movement.

.Further conditioning of the machine for division is effected by the division control arm I282 upon counter-clockwise movement from the position shown in Fig. 18 together with the division conditioning lever I28I, as previously described. Referring to Fig. 15, the division control lever I282 is provided with a depending insulated arm I282b which is positioned adjacent the extended arm I3I6, one arm of a series of arms for switches I3I'I, I3I8, I3I9, and I320. Referring to Figs. 15 and 25, it will be seen that with the division control mechanism in inactive condition and lever I282 in clockwise position shown, the switch I3II of the shift clutch solenoid circuit is closed and the double throw switch I3I8 which is in the division control bridge circuit is in its left-hand position. Also, the switch I3I9 which controls a counter compensation arm disabling magnet I352 is'open and the switch I323 which controls the main reverse magnet is also open. Upon counter-clockwise movement of the division control arm I282 however, the condition of these-switches will all be changed so that abling switch I3I3 and the main reverse switch I320 areclosedv The counter compensation arm disabling magnet I352 (Figs. 6 and has a spring-urged armature I353 (Figs. 6 and 7) carrying a key I354 extending through a slotted portion of the compensator arm shaft and engaging the bottom leg ofa T-shaped slot I355 in the hub "158a of the operating arm I58 (Fig. '5) for the shaft 'Ifldescribed in the application's. N. 12,232. The keyI354 and the slot I355 form a clutch connection whichis normally engaged as shown, but which is disengaged by the energization of magnet I352 so that the counter compensator arms are not affected by a rocking movement of arm 15!! and remain enabled as long as switch I3I9 is closed.

With the machine conditioned as described above division operations are carried out under control of certain division control mechanisms, as will now be described.

14 DIVIDEND SENSING CARRIAGE The dividend sensing mechanism comprises a dividend sensing carriage of the character disclosed in the above-identified application of Harold'T. Avery, S. N. 8l,5"01,to which reference'is made for a disclosure of mechanism not described herein. In general this dividend sensing mechanism comprises a carriage or frame I32l (Fig. l) which is slideably mounted on three shafts I322, I323 and I324 and which has a hub and pin engagementwith a worm shaft I335. Gears I325, I326, and I321 are keyed to the shafts i322 to I324, respectively, and slide on these shafts with the carriage. The gears are ordinally spaced with respect g to each other and each meshes with a respective one of the sensing gear segments I328, I329, and I330. These gear segments are freely pivoted on the worm shaft I335. Rotation of shaft I335 effects ordinal shifting of the division sensing carriage. As seen in Figs. 8 and 9, shaft I335 is driven through gears I356, and I351, and I22 forming a portion of the gear train driven by the previously described step by step movement of ratchet 5H.

Gears I325, I326, and I321 (Fig. 1) are yieldably driven through the respective shafts I322 to I324 by gears I33I, I332, and I333 (Figs. 9 and 15) which have respective spring drive connections i33la, I332a, and 1333a, as described in said Avery application, to each of the shafts i322 through I322, respectively, atthe righthand ends thereof. Gears I331, I332, and I333 in turn mesh with and are driven by a common gear segment I334, (Fig. 15) freelymounted on worm shaft i335 and which segment is operated by the armI3I3 and the link I 3I I, as previously described. a

Asdescribed in the; above Avery application, the result of leftward movement of linkI3II is to drive the segments I328, I329, and i333 (Fig. i) yieldably until they are stopped by engagement with the respective aligned compensator arms 483 of the dividend register so that the position of these segments and correspondingly the respective positions of theshafts I322 to I324 will be representative of the positions occupied by the three aligned compensator arms. The compensator arms are positioned by their associated snail cams during the dividend value sensing operation and therefore the-positions to which shafts I322 to I32 l'are rotated are representative of the values standing in the aligned numeral wheels of the dividend register. At their left-hand ends, the respective shafts I322 to I324 (Fig. 22)

Referring to Fig. 1, the two highest order numeralwheels 23: of the divisor factorindicator $02 have each integral'therewith a-contact .arm

, carry respective contact arms or' brushes I336, I331, and i338 cooperating with. respective series of contacts I339, i340, and I34I which form taps of respective variable resistors: I302, I343, and I344 (Fig. 25) forming part of a. multiple Wheatstone, bridge circuit indicatedi I 346 (Fig. 2) cooperating with a series of contacts I341 forming taps connected to respective variable resistors I348, and I349 (Fig. so that these resistors will be adjusted to represent the two highest order digits of the divisor.

QUOTIEN T ESTIMATIONWHEATSTONE BRIDGE As previously stated, the division control circuits and more particularly the bridge circuits of the instant disclosure are identical in all respects to the similar circuits disclosed in the above noted Avery application, therefore, these circuits will only be briefly described here. The Wheatstone bridge illustrated in Fig. 25 includes two series of variable resistors Rdo and Rdr. The three variable resistors I344, I343, and I342 of the series Rdv are selectively set in accordance with the three leftmost or highest order digits of the dividend or current remainder, while the two variable resistors I348 and I349 of the series Rdr are selectively set in accordance With the two leftmost orders of the divisor as previously described.

The two series of resistors Rdv and Rdr are connected at point X which is, in turn, connected across the bridge to ten taps 0 to 9 on resistor R by ten parallel leads respectively numbered 0 to 9 in Fig. 24. The points of connection at the above taps are established by mathematical formulae disclosed fully in said Avery application and thus establish a plurality of different potentials at the taps on resistor R. The adjustments of the series of resistors Rd?) and Rdr on the other hand establish a selected potential at point X which is representative of the ratio of the resistances in the two series of resistors. By means of the ten parallel leads and related instrumentalities the selected potential at point X is compared with the plurality of potentials on resistor R, and causes energization of a series of electromagnets including the one which is representative of the approximate value of the quotient of dividend and divisor, all as fully described in said Avery application.

The energization of this representative electromagnet in turn controls the number of cycles of operation of the actuating mechanism which subtracts the divisor from the dividend a number of times determined by the pre-estimated quotient digit.

Sensing for an overdraft is controlled in the following manner: A fixed resistor II having resistance corresponding to numeral value of approximately 900 is connected in parallel with the divisor resistors I348 and I349, as explained in said Avery application, and the switch I3I8 switches the resistors I348 and I349 out, and the fixed resistor I35I into the bridge circuit so as to compare the fixed resistance of resistor I 35l with the value of the remainder of the dividend to determine whether an overdraft has occurred and corrective additive cycle is required, or whether the estimated quotient figure was correct and an ordinal shift is to be performed. Following an overdraft, the potential established at point X, by comparison of the Rdv with the fixed resistor I35I will energize the number one bridge magnet I39l (Fig. 24) to control a single cycle of operation of the actuating means While in case of non-overdraft the potential established at point X will determine energization of the zero rragnet I 360, which in turn energizes the shift clutch solenoid 559 to cause shifting of the dividend remainder relative to the divisor.

In the arrangement of the multiple Wheatstone bridge embodied in the machines disclosed in the prior Avery application and also in the present disclosure, a series of bridge magnets I330-I369 (Fig. 24) are energized in a rapid sequence or wave starting with the highest, namely, the #9 magnet, down to and including the one corresponding to the quotient digit.

In said Avery application the bridge magnets directly control the setting of a quotient selection mechanism, and are so arranged that thelowest numbered magnet of the series which is energized controls the quotient selection mechanism, the others above that one being ineffective even though their armatures are ejected.

The bridge magnets of the present machine, on the other hand, are purely relays which are energized in the wave exactly as in said Avery machine and include relay switches which are effective to cause energization of one magnet of the separate series of electro-magnets 35I-859, which one of the magnets so energized corre sponds to the lowest one of the series of bridge relays energized and becomes effective to difierentially adjust the multicyclic latch for the main clutch according to the estimated quotient digit and correspondingly causes a Lire-estimated number of cycles of operation of the main clutch, all as is fully described in th application S. N. 12,232.

DIVISION CONTROL CIRCUIT The normally closed switches I243 (Fig. 24) correspond to the switches of the same number in said Avery application and are opened upon operation of each of the respective relays I368- I368. Each switch, when so opened, opens the circuit to the next higher relay and in so doing cuts out of the bridge circuit all the relays above th one which is representative of the selected quotient digit as described in said Avery application.

The switches which control selective energization of one of the magnets 95I-859 mentioned above, each include a double throw switch associated with and operated by each respective bridge relay magnet I360-I3G8. Each switch includes a normally closed pair of contacts such as those designated I38'Ia and a normally open pair of contacts I381. The contacts I38Ia are connected to the #8 buss 928, but the circuit including this buss is open at the contact I388 of the #8 relay and also at the contact I389 of the #9 relay.

When the Wheatstone bridge is adjusted and set into operation, (and assuming -the quotient digit to be estimated is an 8), only the #9 and #8 relays become energized as described in the above mentioned Avery application. Upon such energization the contacts I389 and I388 are closed by their respective relay magnets and complete the circuit from th main power supply line 9| I, switch I269, and lead I402, to the closed contacts I38Ta and the #8 buss line 928, and therefrom through the actuating winding of the #8 magnet 858, the setting clutch solenoid 93I, switches 5I9 and 648 to ground.

The similar circuit of the #9 magnet 85'! is not closed because at the time the contacts I388 were closed the contacts I388a were opened. Similarly, the circuit for the #7 to #1 magnets 851-851 are not closed because the #7 relay I361 was not energized and its contacts I381 remained open. Thus only the #8 magnet 858 becomes energized under these conditions and'con- 17 trols the cyclic operationpof the machine as described fully hereinbefore.

The bridge relays described above with reference to the wiring diagram are shown in Figs. 11 to 13 and have bias windings which are all energized by a common lead I359 (Fig. 24) and actuating windings which are included in and selectively energized by the bridge circuits described above. Each relay includes an extension of its armature I316 (Figs. 12 and 13) which carries an insulation member I390. This member carries the movable contacts of the three pairs of contacts I240, I383, and I380a, the zero relay being shown in Figs. 12 and 13 for illustration. When the relay is energized, the armature I310 is moved toward the left as viewed in Fig. 13 and in so doing closes contacts I 383 and opens v contacts I240 and I380a to close and open the circuits of the Wiring diagram described above. The armatures of the bridge relays are normally held in the position shown in Fig. 11 by an armature holding slide I39I which is brought to the position shown either by the setting clutch cam 6M (Fig. 25) or by the shift clutch cam 564, and latch-ed in such position by a latch This latch is released by the energization of a solenoid I394, the operation and purpose of which is described hereinafter. When the holding slide I39I is released by the latch I392 and moves toward the left, as seen in Fig. 11 the actuating windings of the division bridge relays which are energized by the bridge circuit overcome the energization of the bias windings and cause counter-clockwise movement of the armatures, whereas the armatures of those relays whose actuating windings are not energized will remain in the illustrated position after release thereof by the hOldlng slide. In the case of a relay whose armature is rocked and the contact I240 is opened, the circuit of the actuating windings of the next higher relays are opened; however, the armatures of these higher relays will remain in their rocked position even though their actuating windings are no longer energized because of the urge of the armature spring 861 and also because these grniatures are out or the effective magnetic field created by the continuous energization of their bias windings. The circuits controlled by the other two pairs of contacts of these relays are therefore not disturbed.

DELAY OF SENSING OPERATIONS It will be recalled that a compensating mechanism becomes operative upon completion of each agitating operation to align the numeral wheels. During division, the compensating mechanism normally operates to align the numeral wheels before a sensing operation is initiated. In case of an overdraft, however, the numeral wheels are changed from zeros to nines and thus cause a carry wave described in U. S. Patent No. 2,222,16 i issued to Harold T. Avery. A mechanism is therefore provided for delaying each dividend value sensing operation fora period of time sufficient to allow any possible carry wave to be completed. In many cases, however, there will be no overdraft; therefore, a second mechanism is provided to supersede the delay mechanism :and initiateasensing operation when the values standing in certain orders of the dividend register indicate that a carry wave through thoseorders is not possible.

Sensing for either quotient pre-estimation or overdraft is controlled by the energization of solenoid I394 (Fig. 25). As long as this solenumeral wheels after an overdraft.

noid is de-energized the armature holding slide I39I is latched by latch I392 and the armatures I3I0-I3'I9 are held in inactive position; there- 'fore, the'armatures cannot operate the switches associated therewith to start the next machine operation. This condition prevails even though the bias and actuating windings of the division bridge magnets may be energized as described hereinbefore.

With the machine conditioned for division as described hereinbe'fore, solenoid I394 (Fig. 25) may beenergized by the closure of any one of the three switches I432, I433, or I434. Switch I432 is under the control of a centrifugally operated brake mechanism which is provided for delaying the return of the numeral wheel centralizer levers until sufficient time has passed forthe compensating mechanism to align the This delay mechanism is operated as follows:

The shaft 468 (Fig. 1), for the centralizer levers 45? of the dividend register has journalled thereon a ratchet I4II (Figs. 21 and 23) which is operated by a pawl I452 .carriedby an arm I4I3secured to the shaft we. The ratchet I4 is secured to a gear Hi4 meshing with a pinion l4l5 which is integral with a gear I4Ii3 (Fig.23)

theseheing journalled on the shaft hill. The gear I4I3 meshes with a pinion i4I8 having its hub journalled on a stub shaft MIG and carrying a gear -l42il which in turn meshes with a pinion I42I freely mounted on the stub shaft I4I1 and'carrying a gear I422 meshing with a pinion I423. The pinion M23 is journalled on the shaft Mill and its hub carries a gear I424 meshing with apinion I425 on the stub shaft will drive through the above gear train to revolve the brake shoes I421.

The latter will revolve about the axis of shaft I4II at a greatly increased speed and by centrifugal force will cause a braking action against the drum I428, thereby retarding the return of the centralizer arms. The gear train is designed to provide a suitable delay in the return of the centralizer arms to allow time for a maximum carry wave to occur.

Also, in order to control the division operation, the arm I4I3 has an extension I43I of in sulating material adapted, in the position of rest of the centralizers, to close switch I432 (Figs. 21 and 25) to thereby energize solenoid I394 and rel-ease the armature holding slide I39I. During an actuating operation, the centraliser arms are rocked out of engagement with their respective numeral wheel gears and switch I432 is opened by such rocking movement.

The switches I433 and M34 (Fig. 22) are in parallel with switch I432 (Fig. 25) and are controlled by the contact arms I33I and I338 of the second (tens) and third (units) orders of the active dividend comparing orders. The two switches I433 and I434 (Figs. 22 and 25) are opened when the second and third active dividend comparing orders stand at zeros. If a value 19 of other than zero stands in either or both of these orders, however, the respective switch or switches I433 and I434 are immediately closed by the dividend sensing operation to complete the circuit to solenoid I394. It will be seen that when a value of other than zero stands in either of these two orders that a carry wave of nines cannot occur and, therefore, there is no need to wait for the centrifugally controlled switch I432 to close before energizing solenoid I394. When these second and third orders both stand at zero, these zeros may be true values, or the zeros may be changed to nines by an overdraft carry wave. In either case the machine has no way of knowing whether or not an overdraft has occurred; therefore, the delaying mechanism shown in Fig. 21 holds the switch I432 open for a length of time suflicient to allow a possible overdraft to occur. If and when such overdraft does occur, the switch arms I331 or I338 will be moved from their to 9 positions and com plete the circuit to solenoid I394 whereas if the overdraft does not occur, these switch arms will not move from their zero positions and the solenoid I394 will not be energized until thecentrifugally controlled delaying mechanism closes switch I432. The timing of the operation of the centrifugally controlled switch I432 may be altered to meet the requirements of the individual machine, but in the preferred embodiment disclosed herein the time required for the closure of this switch is slightly greater than the time required for the completion of a maximum carry wave which is one in which the carry wave origimechanism is equally effective with respect to delaying the operation of the machine when zeros appear in the controlling orders of the dividend remainder after a corrective plus stroke. On the other hand, in those cases where there is no overdraft and a corrective plus stroke is not initiated, the numeral wheels are aligned, at the latest during the shifting operation which follows the sensing of a non-over-draft condition and the centrifugally controlled switch II32 is closed during such shifting to condition the ma-' chine for initiation of the next sensing operation as soon as the shift is completed.

It should also be noted that it is possible to eliminate the switch I434 of the units order of the dividend remainder sensing mechanism and use only the single switch I433 of the tens order for control of the solenoid I384. In the latter case the delays caused by the use of a single order control would be increased nine fold. For example, the machine would be delayed when a zero appeared in the tens order regardless of whether or not the value in the units order were zero or a value from one to nine.

The above described mechanism for delaying a machine operation until the numeral wheels ar properly aligned is disclosed as applied to a crawl carry register having an alignment mechanism of the type disclosed in the previously mentioned Patent No. 2,089,682, in which the numeral wheels may be changed from registration of 0 to "9 during the alignment op eration, but the invention is also applicable to a crawl carry register having an alignment mechanism of the type disclosed in the Gooch Patent No. 1,246,087 issued Nov. 13, 1917, in which the numeral wheels may be changed from registrations of 9 to O by the aligning process.

The principal difference between these aligning mechanisms may be seen by referring to Fig.

1. The dividend register I00 has an aligning mechanism of the first mentioned type, while the register IfiI has an aligning mechanism of the Gooch type. It will be noted that with the nu meral wheels of both registers in their respec" tive normal 0 positions, the compensating arm 483 of the dividend register I58 lies on the extreme high portion of its associated snail cam 482, whereas, the compensating arm 156 of the counter register IIlI lies on the extreme low portion of its associated snail cam I24.

In each of these registers a crawl carry gearing between adjacent numeral wheels serves to 7 advance each higher order numeral wheel in i proportion to the advance of the next lower order numeral wheel. In the case of the dividend register IE6, if a series of numeral wheels 46I have true values of 9 after actuation thereof, then the numeral wheels of this series each stand at substantially 0 due to the crawl carry gearing between the orders. In this case the machine does not know whether or not the Os are true Os or whether the will be changed to 9s, and the previously described delaying mecha nism is operative to delay the next successive machine operation until the aligning process is completed.

In the case of the register IGI however, a series of numeral wheels which have true values of 0 after an actuation thereof stand in the 9s position, as described in said Gooch patent. Therefore, if the aligning mechanism for the counter register IIlI were substituted for use in the dividend register I 00, then the delaying mechanism would be controlled in such a manner that when a series of numeral wheels each registered values of 9, the succeeding machine operation would be delayed until the aligning process either changed these 9s to Os or until it is determined that these 9s are true values. In the latter case the operation of the switches I433 and I434 (Fig. 25) would be such that they would be held open when the controlling orders thereof registered extreme settings of 9 and would be closed by the aligning movement of the numeral wheels from 9" to 0- It will be understood that the centrifugally controlled delay of the centralizer arms is of general utility in registers embodying springdriven tens transfer mechanism to insure a correct reading of the values when a carry wave occurs in any operation. This is true because a premature return of the centralizer arms can interrupt the spring-driven overdraft carry wave and cause an erroneous registration.

In machines employing crawl type tens carry mechanisms in the dividend register, sensing operations are dependent upon the proper alignment of the numeral wheels of this regis ter; therefore, all of such sensing operations normally are delayed until the numeral wheels are properl aligned. From the foregoing description of the delay mechanism and related switches operated by such mechanism it will be 

